﻿// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Drawing;
using System.Windows.Forms.VisualStyles;

namespace System.Windows.Forms;

/// <summary>
///  This class contains the information a user needs to paint ListView
///  column header (Details view only).
/// </summary>
public class DrawListViewColumnHeaderEventArgs : EventArgs
{
    /// <summary>
    ///  Creates a new DrawListViewColumnHeaderEventArgs with the given parameters.
    /// </summary>
    public DrawListViewColumnHeaderEventArgs(
        Graphics graphics,
        Rectangle bounds,
        int columnIndex,
        ColumnHeader? header,
        ListViewItemStates state,
        Color foreColor,
        Color backColor,
        Font? font)
    {
        Graphics = graphics.OrThrowIfNull();
        Bounds = bounds;
        ColumnIndex = columnIndex;
        Header = header;
        State = state;
        ForeColor = foreColor;
        BackColor = backColor;
        Font = font;
    }

    /// <summary>
    ///  Graphics object with which painting should be done.
    /// </summary>
    public Graphics Graphics { get; }

    /// <summary>
    ///  The rectangle outlining the area in which the painting should be done.
    /// </summary>
    public Rectangle Bounds { get; }

    /// <summary>
    ///  The index of this column.
    /// </summary>
    public int ColumnIndex { get; }

    /// <summary>
    ///  The header object.
    /// </summary>
    public ColumnHeader? Header { get; }

    /// <summary>
    ///  State information pertaining to the header.
    /// </summary>
    public ListViewItemStates State { get; }

    /// <summary>
    ///  Color used to draw the header's text.
    /// </summary>
    public Color ForeColor { get; }

    /// <summary>
    ///  Color used to draw the header's background.
    /// </summary>
    public Color BackColor { get; }

    /// <summary>
    ///  Font used to render the header's text.
    /// </summary>
    public Font? Font { get; }

    /// <summary>
    ///  Causes the item do be drawn by the system instead of owner drawn.
    /// </summary>
    public bool DrawDefault { get; set; }

    /// <summary>
    ///  Draws the header's background.
    /// </summary>
    public void DrawBackground()
    {
        if (Application.RenderWithVisualStyles)
        {
            VisualStyleRenderer vsr = new(VisualStyleElement.Header.Item.Normal);
            vsr.DrawBackground(Graphics, Bounds);
        }
        else
        {
            using (var backBrush = BackColor.GetCachedSolidBrushScope())
            {
                Graphics.FillRectangle(backBrush, Bounds);
            }

            // Draw the 3d header
            Rectangle r = Bounds;

            r.Width -= 1;
            r.Height -= 1;

            // Draw the dark border around the whole thing
            Graphics.DrawRectangle(SystemPens.ControlDarkDark, r);

            r.Width -= 1;
            r.Height -= 1;

            // Draw the light 3D border
            Graphics.DrawLine(SystemPens.ControlLightLight, r.X, r.Y, r.Right, r.Y);
            Graphics.DrawLine(SystemPens.ControlLightLight, r.X, r.Y, r.X, r.Bottom);

            // Draw the dark 3D Border
            Graphics.DrawLine(SystemPens.ControlDark, r.X + 1, r.Bottom, r.Right, r.Bottom);
            Graphics.DrawLine(SystemPens.ControlDark, r.Right, r.Y + 1, r.Right, r.Bottom);
        }
    }

    /// <summary>
    ///  Draws the header's text (overloaded)
    /// </summary>
    public void DrawText()
    {
        HorizontalAlignment hAlign = Header?.TextAlign ?? HorizontalAlignment.Left;
        TextFormatFlags flags = (hAlign == HorizontalAlignment.Left) ? TextFormatFlags.Left :
                                ((hAlign == HorizontalAlignment.Center) ? TextFormatFlags.HorizontalCenter :
                                 TextFormatFlags.Right);
        flags |= TextFormatFlags.WordEllipsis;

        DrawText(flags);
    }

    /// <summary>
    ///  Draws the header's text (overloaded) - takes a TextFormatFlags argument.
    /// </summary>
    public void DrawText(TextFormatFlags flags)
    {
        string? text = Header?.Text;
        int padding = TextRenderer.MeasureText(" ", Font).Width;
        Rectangle newBounds = Rectangle.Inflate(Bounds, -padding, 0);

        TextRenderer.DrawText(Graphics, text, Font, newBounds, ForeColor, flags);
    }
}
